1. Field of the Invention
The present invention relates to a process of the preparation of 2-methyl-3-prenyl-4,5,6-trimethoxyphenol of general formula (I): ##STR3## wherein R represents a group of the formula: ##STR4## N BEING AN INTEGER OF 0-9, AND A and B represent hydrogen atom or A--B may form a bond. Compound (I) is a useful intermediate of 2,3-dimethoxy-5-methyl-6-prenyl-1,4-benzoquinone of general formula (II): ##STR5## wherein R has the same meaning as above.
Compound (II) is known as coenzyme Q. Particularly, 2,3-dimethoxy-5-decaprenyl-6-methyl-1,4-benzoquinone of the formula wherein A and B together form a bond and n is 9 [2,3-dimethoxy-5-(3,7,11,15,19,23,27,31,35,39-decamethyltetracontadecaene- 2,6,10,14,18,22,26,30,34,38-yl)-6-methyl-1,4-benzoquinone] called "coenzyme Q.sub.10 " takes part in electron transport system in vivo and it also plays a very important role in energy generation. Coenzyme Q.sub.10 improves disorder in the myocardium tissue due to ischemia, increases cardiac minute volume which has once decreased and exhibits antagonism against Na retention of aldosterone. Coenzyme Q.sub.10 is thus effective for the prevention and treatment of congestive cardiac insufficiency, congestion of the lung, swelling of the liver and angina pectoris.